Screw driving device



May 26, 1931.

J. V. WALKER SCREW DRIVING DEVICE `F'1ed 001'.. 9. 1929 AAA 4M j Z/ MMM INVENTOR.

ATTORNEYS.

Patented May 26.1931

UNITED STATES] PATENT OFFICE JOHN V. WALKER, OF IAIRVIEW, PENNSYLVANIA, ASSIGNOR T TITAN TOOL COI- PANY, OP'EBIE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA scnEw DRIvING DEVICE Application led October l9, 1929. Serial No. 398,547.

head during the engaging and releasing movement. The present invention is designed to obviate this difficulty by providing an independent clutch for locking the jaws rotatively with the head so that the rotative locking may be accomplished independently of the axial movement of the jaws. In this way, the

jaws may be engaged and released without injury to the thread studs and in a smooth and eilicient manner. Features and details of the invention will appear from the specification and claims.

A- preferred embodiment ofthe invention is illustrated in the accompanying drawingsl as follows:-

Fig. 1 shows a central section of the device with the driver in position to drive a stud.

Fig. 2 a similar section at the completion of the driving movement.

Fig 3 a similar section with the jaws released.

Fig. 4 a section on the line 4--4 in Fig. 2.

1 marks the head whichin use is connected to a driving spindle. It has the jaw-receiving socket 2 in which jaws 3 are placed.I These jaws are movable axially in the socket and are also free to rotate except when locked in the manner hereinafter described. The jaws are separable. The device as shown comprises three jaws. They have a groove 4 at their rea-r ends in which is arranged a spring ring 5 which holds the jaws in proper register. The jaws are internally screw-threaded at 6 at their front ends' and are provided with exterior cam closing surfaces 7 at their front ends engaging similar surfaces 8 at the end 50 of the head. The jaws have the internal forced inwardly are brought into these poropening cam surfaces 9 at the rear of the threads 6.

An opening lunger has a cam surface 10 at its front en engaging the cam surfaces 9 and opening the jaws when the jaws are withdrawn from the socket. The cam surfaces 10 are on a yielding extension 10a which is secured by a pin 11 with a sliding plug 13. The plug 13 is slidinglymounted in a bore 14 in the head and has a head 15. The head 15 has ribs 13a which extend into the spaces between the jaws and keeps the jaws in spaced relation j so that they will open and close freely. The head 15 extends i-nto grooves 3a in the jaws so that the plunger 13 is locked to move with the jaws. A spring 12 yieldingly urges the extension 10er forward so as to crowd the jaws into open positionthrough the action of the cam surfaces 10 when the jaws are withdrawn from the socket. The pin 11 Iis provided with a head 11a and the pin is of such length as to give the extension the necessary freedom of movement relatively to the plug 13 and the jaws 3 to accomlish the opening movement of the jaws. lutch balls 16 are slidingly mounted in radial openings 17 in the head. The jaws have raised portions 19 which terminate in driving shoulders 18 and the balls when tions and thus into driving relation with the jaws. l An actuating sleeve 21 is slidingly mountedon the head. This has a ball-receiving recess 22 which terminates in a cam surface 23. The recess is sufficient to permit the balls to pass outwardly under the camming action of the shoulder 18 and centrifugal force so as to release the jaws and permit them to rotate relatively to the head. The cam 23 forces the balls into locking position when the sleeve is moved forward. A spring 24 yieldingly urges the sleeve forward to force the balls into locking position. A latch 25 is arranged in a socket 25a in the head. This latch has a shoulder 26 which limits the forward movement of the sleeve 21 and also through the action of a catch shoulder 27. The latch also has a projection 28 which is adapted to engage the catch shoulder 27 when the sleeve is retracted. A spring 29`yield- 100 ingly forces the latch outwardly into locking position. The sprngis seated on a sliding plug 30 which has a cam end 31 which,

, with the plug- 30 seated, is in the path of the plu 13.

T e sleeve 21 has a projection 21a which is adapted to engage the work as the device advances so as to retract the sleeve and release the clutch -at a pre-determined position. This pre-determined position places the locking shoudder 27 over the catch 28. VThis locking out has a functional purpose hereinafter specified. In operating the device, the stud is initially set in the work, as indicated in Fig. 1. The driver parts are in the position shown in Fig. 3 and this is placed over the stud and the driver forced forwardly. As the driver is pushed forward, the end of the stud contacts the extension 10a and at the limit of its movement the plug and jaws are.l

forced inwardly to the position shown in Fig. 1. During this inward movement the jaws are being rotated because the clutch balls are in their lnner, o r set position. This is desirable in that the threads are then certainly brought into register. The spindle continues in operation driving the stud to the position shown in Fi 2, when the projection 21 has advanced su ciently to retract the sleeve 21 to the position shown in Fig. 2,- and this releases the balls 16, the balls acting both under centrifugal force and the camming action of the shoulders 18. The operator then withdraws the driving device. In the interval during which the jaws are bein withdrawn and before they reach the positlon of disengagement from the thread the catch 28 retains the sleeve 2l in its retracted position and consequently the jaws are stationary, or not being driven by the balls. This prevents any shock, or chatter between the balls and the shoulders 18 as this disengagement is taking place. As

' soon as the plug 13 is withdrawn from under the seat 30, the spring 29 is so released that the spring `24 overcomes the resistance of the A shoulder 28 and the sleeve snaps to its forward position driving the balls to their inward position, the balls being received by a groove, or recess 32 which extends entirely around the jaws.

What I claim as new is 1. In a screw driving device, the combination of a head having a jaw socket; separable jaws axially movable and rotatable in the socket and closed by the walls of the socket as drawn thereinto; a clutch mechanism locking the jaws rotatively with the head; and means actuating the clutch mechanism indepen dently of the movement of the aws relatively to the head.

2. In a screw driving device. the combination of a head having a jaw socket; separable jaws axially movable and rotatable in the socket and closed by the walls of the socket as drawn thereinto; a clutch mechanism lockwith the driving device and actuated at a' pre-determined point of advancement.

3. In a screw driving device, the combination of-a head having a jaw socket; separable jaws axially movable and rotatable in the socket v"and closed by the walls of the socket as drawn thereinto; a clutch mechanism locking the jaws rotatively with the head; means actuating the clutch mechanism independently of the movement of the jaws relatively to the head; and means comprising a sleeve slidingly mounted on the hea and advanced with the driving device and actuated at a pre-determined point of advancement. n'

4. Ina'screw driving device, the combination -of a head having a jaw-receiving socket; separable jaws axially and rotatively mounted in the socket, said 'aws having raised ortions and closing as d clutch devices in the wall of the head movable into and out of said rtions; and means on the head actuating said clutch devices.

5. In a screw driving device, the combination of a head havin a j aw-receiving socket; separable jaws axial y and rotatively mounted in the socket, said j'aws having raised tions and closing as drawn into said soc et; clutch devices in the wall of the head movable into and out of said portions; and means on the head actuating said clutch devices, said` means comprising a sleeve slidingly mounted on the head and having an interlo'r recess receiving the clutch devices to release the jaws, and a cam surface acting on the clutch devices.

6. In a screw driving device, the combination of a head havin a j aw-receiving socket; separable jaws axia y and rotatively mounted in the socket, said 'aws having raised portions and closing as awn into said sockets; clutch devices in the wall of the head movable into and out of said'portions; and means on the head actuating said clutch devices, said means comprising a sleeve slidingly mountrawn into said soc et;

vices, and a latch locking the sleeve in rei leased position, said latch being released as the jaws are withdrawn from the socket.

7. In a screw driving device, the combination of a head having a jaw-receiving socket; separable jaws axially and rotatively mounted in the socket, said 'aws having raised tions and closing as drawn into said soc et; clutch devices'in the wall of the head movable into and out of said portions; and means on the head actuating said clutch devices, said means comprisin a sleeve slidingly mounted on the head and aving an interior recess receiving the clutch devices to release the jaws,

a cam surface acting on the clutch devices, a jaw separatingl plug movable with the jaws and opening t drawn from the socket, a latch in the head locking the sleeve in closed position, and means releasing the latch with a movement of the plug as the jaws are withdrawn.

8. In a screw driving device, the combination of a head having a jaw-receiving socket; separable jaws axially and rotatively mounted in the socket, said jaws having raised portions and closing as drawn into said socket; clutch devices in the wall of the head movable into and out of said portions; and means on the head slidingly mounted on the head and having an interior recess receiving the clutch devices to release the jaws, a cam surface acting on the clutch devices, and a jaw separating plug movable with the jaws, said plug having a spring-pressed extension moving relatively to the jaws and opening the same as the jaws are withdrawn from the socket.

9. In a screw driving device, the combination of a head havin a jaw-receiving socket; se arable jaws axially and rotatively mounte in the socket, said jaws having raised portions and closing as drawn into said socket; clutch devices in the Wall of the head movable into and out of said portions; and means on the head slidingly mounted on the head and havin an interior recess receiving the clutch devices to release the jaws, a cam surface acting on the clutch devices, a jaw se arating plug movable with the jaws, said p ug having a spring-pressed extension moving relatively to the jaws and o ning the same as the jaws are withdrawn flim the socket;

' a latch in the head locking the sleeve in rewith a movement of a leased position; and means releasing the latch lu as the 'aws are withdrawn. P g J In testimony whereof I have hereunto set my hand.

JOHN V. WALKER.

e same as the jaws are with- 

